The present invention pertains to seismic data processing and more particularly to processing seismic data obtained from seismic cables set on land or under a body of water where multi-axial geophones are used at each single receiver location. The present invention pertains to changing the orientation of multicomponent seismic detectors and more particularly to the use of data manipulation and the rotation of the orientation of seismic detectors to remove errors and noise from detected data.
Multicomponent detectors are generally composed of three geophones: two orthogonal horizontal geophones and one vertical geophone. There are various problems in the orientation of these multicomponent geophone assemblies. One problem is due to shot position errors, or the location of the shot or source with respect to the detectors. A further problem occurs in marine environment. When the array is laid on the ocean bottom, various ocean floor inconsistencies, such as rocks, coral, etc., can misalign the intended orientation. Still another problem relates to coupling errors between the geophones and the earth.
There have been attempts at dealing with the determination of receiver orientation angle. However, even under these methods, there is still some error. Even if the residual error is on the order of a few degrees, it still needs to be addressed.
An example of prior art efforts to compensate for coupling discrepancies in seismic data acquisition is U.S. Pat. No. 5,724,307, incorporated herein by reference, titled "Method for Improving the Coupling Response of a Water Bottom Seismic Sensor" issued to James E. Gaiser. This reference relates to providing a receiver-consistent deconvolution operator that models the damped oscillatory wavetrain which is related to geophone coupling to the water bottom. The operator described is a best-fitting function that endeavors to describe the difference in coupling response between a well coupled first geophone relative to an imperfectly coupled second geophone. The operator is applied to the second signals to compensate the signals for the distortion due to imperfect second ground coupling.